WEBVTT 1 00:00:00.240 --> 00:00:01.073 In this lesson, 2 00:00:01.073 --> 00:00:02.910 we're going to talk about boot options 3 00:00:02.910 --> 00:00:06.600 that are set inside of your BIOS or UEFI. 4 00:00:06.600 --> 00:00:10.050 Now the BIOS or basic input/output system is the program 5 00:00:10.050 --> 00:00:12.960 that a personal computer's microprocessor is going to use 6 00:00:12.960 --> 00:00:15.480 to get that computer system started and booted up 7 00:00:15.480 --> 00:00:17.220 after you turn it on. 8 00:00:17.220 --> 00:00:19.560 This BIOS is also going to manage the data flow 9 00:00:19.560 --> 00:00:21.240 between the computer's operating system 10 00:00:21.240 --> 00:00:23.820 and the attached devices such as the storage devices 11 00:00:23.820 --> 00:00:26.340 like a hard disk drive, or solid-state drive, 12 00:00:26.340 --> 00:00:29.460 a video adapter, the keyboard and the printer. 13 00:00:29.460 --> 00:00:31.800 This is the most common example of firmware 14 00:00:31.800 --> 00:00:33.330 or software on a chip 15 00:00:33.330 --> 00:00:35.700 and it is the first software that's run by the computer 16 00:00:35.700 --> 00:00:37.830 whenever you power on the machine. 17 00:00:37.830 --> 00:00:39.720 Now the BIOS has several roles 18 00:00:39.720 --> 00:00:42.180 including performing the power-on self-test 19 00:00:42.180 --> 00:00:44.700 which is going to test and initialize the processor, 20 00:00:44.700 --> 00:00:47.340 videocard, disk drives and adapters, 21 00:00:47.340 --> 00:00:49.410 as well as configuring the hardware of your system 22 00:00:49.410 --> 00:00:51.120 and setting up the proper boot order 23 00:00:51.120 --> 00:00:54.360 to execute when that system is first powered on. 24 00:00:54.360 --> 00:00:58.530 The BIOS is stored in ROM and ROM is read-only memory. 25 00:00:58.530 --> 00:00:59.363 This is a type of chip 26 00:00:59.363 --> 00:01:01.740 that is actually embedded into your motherboard 27 00:01:01.740 --> 00:01:05.610 but it can be upgraded through a process known as flashing. 28 00:01:05.610 --> 00:01:09.060 The BIOS is also a program inside of this chip 29 00:01:09.060 --> 00:01:10.650 and that program allows the user 30 00:01:10.650 --> 00:01:12.330 to make changes to the settings 31 00:01:12.330 --> 00:01:14.220 and those settings are going to be saved 32 00:01:14.220 --> 00:01:16.380 in something known as the CMOS. 33 00:01:16.380 --> 00:01:20.220 The CMOS is the complementary metal-oxide semiconductor 34 00:01:20.220 --> 00:01:22.500 and it's a battery-powered memory chip. 35 00:01:22.500 --> 00:01:24.390 This is a non-volatile type of memory 36 00:01:24.390 --> 00:01:25.860 that stores the BIOS settings 37 00:01:25.860 --> 00:01:27.900 and it's built into the motherboard. 38 00:01:27.900 --> 00:01:29.940 As long as the battery power remains, 39 00:01:29.940 --> 00:01:32.430 the DC current is going to be provided to the CMOS 40 00:01:32.430 --> 00:01:34.230 and this allows the settings to be retained 41 00:01:34.230 --> 00:01:37.080 by that motherboard and by that BIOS. 42 00:01:37.080 --> 00:01:39.330 If the computer is constantly losing its settings 43 00:01:39.330 --> 00:01:40.950 or forgetting the date and time, 44 00:01:40.950 --> 00:01:42.300 this is usually an indication 45 00:01:42.300 --> 00:01:44.550 that that battery needs to be replaced. 46 00:01:44.550 --> 00:01:47.100 This battery normally lasts about three years. 47 00:01:47.100 --> 00:01:48.600 But on newer CMOSs, 48 00:01:48.600 --> 00:01:51.300 these can actually use an internal lithium-ion battery 49 00:01:51.300 --> 00:01:53.460 that can last up to 10 years. 50 00:01:53.460 --> 00:01:54.960 The most typical external battery 51 00:01:54.960 --> 00:01:56.910 that's going to be used with these CMOSs 52 00:01:56.910 --> 00:01:59.430 is known as the CR2032 53 00:01:59.430 --> 00:02:01.410 and this looks like a watch battery. 54 00:02:01.410 --> 00:02:03.930 Now remember, if the battery begins to fail, 55 00:02:03.930 --> 00:02:05.550 the first thing the user is going to notice 56 00:02:05.550 --> 00:02:06.780 is that that system clock 57 00:02:06.780 --> 00:02:09.120 is going to forget the date and time frequently. 58 00:02:09.120 --> 00:02:11.790 So if you find yourself changing your date and time a lot, 59 00:02:11.790 --> 00:02:15.120 this indicates that your battery is most likely dying. 60 00:02:15.120 --> 00:02:17.310 Now when you press the power button on your computer, 61 00:02:17.310 --> 00:02:19.740 the first thing that happens when power is applied 62 00:02:19.740 --> 00:02:21.600 is we begin the boot process 63 00:02:21.600 --> 00:02:24.330 and the first step is the power-on self-test 64 00:02:24.330 --> 00:02:26.160 which is known as the POST. 65 00:02:26.160 --> 00:02:29.490 The power-on self-test is a diagnostic testing sequence 66 00:02:29.490 --> 00:02:31.860 that a computer's basic input/output system 67 00:02:31.860 --> 00:02:33.240 or the starting program 68 00:02:33.240 --> 00:02:36.030 is going to run to determine if the computer's keyboard, 69 00:02:36.030 --> 00:02:39.780 RAM, disk drives, storage devices and other hardware 70 00:02:39.780 --> 00:02:41.670 are all working properly. 71 00:02:41.670 --> 00:02:43.560 If the necessary hardware is detected 72 00:02:43.560 --> 00:02:45.420 and it's found to be operating properly, 73 00:02:45.420 --> 00:02:47.730 that computer can then begin to boot up. 74 00:02:47.730 --> 00:02:49.530 If the hardware is not detected 75 00:02:49.530 --> 00:02:52.050 or it's found to not be operating properly, 76 00:02:52.050 --> 00:02:53.850 the BIOS will issue an error message 77 00:02:53.850 --> 00:02:56.370 which could be a text message on your screen. 78 00:02:56.370 --> 00:02:58.410 Or if your screen is having a problem, 79 00:02:58.410 --> 00:03:00.450 it could be a series of coded beeps 80 00:03:00.450 --> 00:03:03.240 depending on the nature of your specific problem. 81 00:03:03.240 --> 00:03:04.073 Since the POST 82 00:03:04.073 --> 00:03:06.600 runs before the computer's video card is activated, 83 00:03:06.600 --> 00:03:09.690 it may not be possible to display everything to your screen. 84 00:03:09.690 --> 00:03:12.180 And therefore, we're going to use these variable beeps 85 00:03:12.180 --> 00:03:15.120 as a way to tell you what's wrong with the system. 86 00:03:15.120 --> 00:03:17.040 These beeps can be short and long 87 00:03:17.040 --> 00:03:19.320 or a mixture of short and long beeps 88 00:03:19.320 --> 00:03:21.210 depending on what type of BIOS is installed 89 00:03:21.210 --> 00:03:22.620 by your motherboard. 90 00:03:22.620 --> 00:03:25.200 The exact pattern of beeps is going to contain messages 91 00:03:25.200 --> 00:03:27.270 about the nature of the problem that it found. 92 00:03:27.270 --> 00:03:29.760 For example, if the keyboard is not detected, 93 00:03:29.760 --> 00:03:32.280 a particular pattern of beeps might inform you of that 94 00:03:32.280 --> 00:03:34.620 by sending two short and one long beep, 95 00:03:34.620 --> 00:03:37.110 something like beep, beep, boop. 96 00:03:37.110 --> 00:03:39.630 Now the POST can also have errors that are fatal. 97 00:03:39.630 --> 00:03:40.680 And if this is the case, 98 00:03:40.680 --> 00:03:42.810 it'll cause the current program to stop running 99 00:03:42.810 --> 00:03:44.700 and it will halt the boot process. 100 00:03:44.700 --> 00:03:45.960 This is important to understand 101 00:03:45.960 --> 00:03:48.810 because the hardware that's being checked by this POST test 102 00:03:48.810 --> 00:03:50.460 is all the essential hardware, 103 00:03:50.460 --> 00:03:52.560 things like your memory, your keyboard, 104 00:03:52.560 --> 00:03:55.680 your input/output devices and your processor. 105 00:03:55.680 --> 00:03:58.230 So if there's any error in any of these things, 106 00:03:58.230 --> 00:04:00.750 it will stop the boot process because it can't go 107 00:04:00.750 --> 00:04:02.250 and load a full operating system 108 00:04:02.250 --> 00:04:04.050 with faulty hardware. 109 00:04:04.050 --> 00:04:06.810 Now once your POST does successfully happen, 110 00:04:06.810 --> 00:04:07.950 this will then allow the BIOS 111 00:04:07.950 --> 00:04:09.660 to read the settings from the CMOS 112 00:04:09.660 --> 00:04:11.760 and the BIOS will then look for an operating system 113 00:04:11.760 --> 00:04:13.860 from your configured boot devices. 114 00:04:13.860 --> 00:04:17.070 The BIOS also has its own low-level operating system 115 00:04:17.070 --> 00:04:18.510 of sorts for that computer 116 00:04:18.510 --> 00:04:20.010 which allows it to take input 117 00:04:20.010 --> 00:04:22.470 and give output to the most basic components 118 00:04:22.470 --> 00:04:24.300 including your keyboard, your disk drives, 119 00:04:24.300 --> 00:04:25.860 and the video display. 120 00:04:25.860 --> 00:04:28.770 Using its low-level ability to read from the storage device, 121 00:04:28.770 --> 00:04:30.060 the BIOS will then try to find 122 00:04:30.060 --> 00:04:31.740 your installed operating system, 123 00:04:31.740 --> 00:04:34.740 something like Windows or Linux or Mac OS. 124 00:04:34.740 --> 00:04:36.480 And then, the operating system's bootloader 125 00:04:36.480 --> 00:04:39.210 is going to begin the operating system boot up process 126 00:04:39.210 --> 00:04:40.890 and turns over control the computer 127 00:04:40.890 --> 00:04:42.870 over to that operating system. 128 00:04:42.870 --> 00:04:45.900 Now the BIOS also stores its settings and configurations 129 00:04:45.900 --> 00:04:48.030 in the CMOS like I said before 130 00:04:48.030 --> 00:04:49.909 but you're probably wondering, 131 00:04:49.909 --> 00:04:51.090 how do you change those settings? 132 00:04:51.090 --> 00:04:53.880 Well, to configure those settings inside of the CMOS, 133 00:04:53.880 --> 00:04:56.730 you need to enter the BIOS configuration environment. 134 00:04:56.730 --> 00:04:59.250 To do this, you're going to be pressing a valid key 135 00:04:59.250 --> 00:05:02.040 or combination keys during the boot up process 136 00:05:02.040 --> 00:05:03.000 and this is going to be set up 137 00:05:03.000 --> 00:05:05.370 by your manufacturer of your BIOS. 138 00:05:05.370 --> 00:05:08.670 The most commonly used keys for this is F2 or Delete 139 00:05:08.670 --> 00:05:10.890 but this does vary depending on the BIOS 140 00:05:10.890 --> 00:05:12.630 and the motherboard that you're using 141 00:05:12.630 --> 00:05:15.443 and I've seen other keys like the Escape key, F1, 142 00:05:15.443 --> 00:05:18.270 F10 and F12 being used. 143 00:05:18.270 --> 00:05:20.400 Usually, when you first turn on the system, 144 00:05:20.400 --> 00:05:21.840 there will be a message on your screen 145 00:05:21.840 --> 00:05:23.940 that will tell you which keystroke is required 146 00:05:23.940 --> 00:05:26.250 in order to change its configuration settings. 147 00:05:26.250 --> 00:05:27.810 If you don't see that displayed, 148 00:05:27.810 --> 00:05:29.730 you can simply do a quick search online 149 00:05:29.730 --> 00:05:31.320 at the manufacturer's website 150 00:05:31.320 --> 00:05:33.330 and this will tell you which keystroke is being used 151 00:05:33.330 --> 00:05:35.100 by your particular system. 152 00:05:35.100 --> 00:05:38.250 Now traditionally, there was only a single type of BIOS 153 00:05:38.250 --> 00:05:40.740 which relied fully on a text-based menu system 154 00:05:40.740 --> 00:05:43.110 and a keyboard as its system of input. 155 00:05:43.110 --> 00:05:45.600 This traditional BIOS provided the user with the ability 156 00:05:45.600 --> 00:05:48.240 to view information on memory, CPU, 157 00:05:48.240 --> 00:05:50.610 optical drives and storage devices. 158 00:05:50.610 --> 00:05:52.620 While these weren't very graphically appealing, 159 00:05:52.620 --> 00:05:53.790 these text-based systems 160 00:05:53.790 --> 00:05:56.160 did provide all the necessary functionality 161 00:05:56.160 --> 00:05:58.800 in order to configure your device, your boot order, 162 00:05:58.800 --> 00:06:01.290 your clock speeds, the date, the time, 163 00:06:01.290 --> 00:06:03.840 whether or not you're going to enable virtualization support, 164 00:06:03.840 --> 00:06:06.870 security features and lots of other things like that. 165 00:06:06.870 --> 00:06:08.220 Now modern systems though 166 00:06:08.220 --> 00:06:10.740 have started switching over from this traditional BIOS 167 00:06:10.740 --> 00:06:14.280 and instead are using something known as the UEFI. 168 00:06:14.280 --> 00:06:17.670 Now the UEFI or UEFI as we like to call it 169 00:06:17.670 --> 00:06:20.027 is the Unified Extensible Firmware Interface 170 00:06:20.027 --> 00:06:22.649 and it's basically an updated form of BIOS 171 00:06:22.649 --> 00:06:25.680 that allows both the keyboard and mouse as input, 172 00:06:25.680 --> 00:06:27.960 as well as providing a graphical user interface 173 00:06:27.960 --> 00:06:30.570 instead of that standard text-based menu. 174 00:06:30.570 --> 00:06:33.270 These systems tend to be more intuitive for you to use 175 00:06:33.270 --> 00:06:35.190 because they have that graphical user interface 176 00:06:35.190 --> 00:06:37.200 instead of a text-based menu system 177 00:06:37.200 --> 00:06:39.810 and they still provide all the necessary functionality 178 00:06:39.810 --> 00:06:42.060 to configure your devices, your boot order, 179 00:06:42.060 --> 00:06:44.220 your clock speeds, your date and time, 180 00:06:44.220 --> 00:06:46.740 the virtualization support options, security features, 181 00:06:46.740 --> 00:06:49.530 and lots of other things including rates. 182 00:06:49.530 --> 00:06:51.150 Now some of these UEFI-based systems 183 00:06:51.150 --> 00:06:52.890 also include software in them 184 00:06:52.890 --> 00:06:54.330 that will allow you to go online, 185 00:06:54.330 --> 00:06:55.470 play some basic games, 186 00:06:55.470 --> 00:06:56.850 and even use backup programs 187 00:06:56.850 --> 00:06:59.610 without ever having to enter into a normal operating system 188 00:06:59.610 --> 00:07:02.040 like Windows, Linux or Mac OS, 189 00:07:02.040 --> 00:07:04.080 and this makes them very powerful. 190 00:07:04.080 --> 00:07:07.500 Now UEFI has several advantages over the traditional BIOS. 191 00:07:07.500 --> 00:07:09.720 First, the traditional BIOS only operates 192 00:07:09.720 --> 00:07:11.460 as a 32-bit system 193 00:07:11.460 --> 00:07:14.520 whereas UEFI can support 64-bit systems. 194 00:07:14.520 --> 00:07:17.460 Second, UEFI can support larger hard disk drives 195 00:07:17.460 --> 00:07:19.170 and solid-state devices. 196 00:07:19.170 --> 00:07:21.720 The traditional BIOS can only support storage devices 197 00:07:21.720 --> 00:07:24.180 up to 2.2 terabytes in size 198 00:07:24.180 --> 00:07:25.860 but the UEFI can support drives 199 00:07:25.860 --> 00:07:28.830 up to 9.4 zettabytes in size. 200 00:07:28.830 --> 00:07:32.310 That is 9.4 times 10 to the 21st bytes. 201 00:07:32.310 --> 00:07:34.740 That would be a an extremely large drive. 202 00:07:34.740 --> 00:07:37.230 And right now, none of those actually exist. 203 00:07:37.230 --> 00:07:38.430 But for this reason, 204 00:07:38.430 --> 00:07:41.790 UEFI gives us lots of capability well into the future. 205 00:07:41.790 --> 00:07:44.100 The third thing we have is that the traditional BIOS 206 00:07:44.100 --> 00:07:46.350 only supports using a master boot record 207 00:07:46.350 --> 00:07:47.820 which is known as an MBR 208 00:07:47.820 --> 00:07:50.160 and this is your storage device partition table 209 00:07:50.160 --> 00:07:51.780 that tells you how the things are stored 210 00:07:51.780 --> 00:07:54.720 on your given hard drive or solid-state device. 211 00:07:54.720 --> 00:07:57.240 But UEFI can actually support the newer GUID 212 00:07:57.240 --> 00:08:00.090 or GUID partition table format 213 00:08:00.090 --> 00:08:02.250 which is known as the GPT. 214 00:08:02.250 --> 00:08:05.670 Now this new format of GPT supports larger hard disks 215 00:08:05.670 --> 00:08:08.250 and storage devices as required for any device 216 00:08:08.250 --> 00:08:11.580 that is going to be larger than 2.2 terabytes in size. 217 00:08:11.580 --> 00:08:14.850 Fourth, the UEFI tends to be faster than a traditional BIOS 218 00:08:14.850 --> 00:08:16.410 in terms of booting up a system. 219 00:08:16.410 --> 00:08:18.720 So this is another increased benefit for us. 220 00:08:18.720 --> 00:08:22.320 And fifth, the UEFI usually uses a larger size ROM 221 00:08:22.320 --> 00:08:23.670 than a traditional BIOS. 222 00:08:23.670 --> 00:08:25.950 And so it can actually support more complicated programs 223 00:08:25.950 --> 00:08:27.870 including that GUI-based configuration tool 224 00:08:27.870 --> 00:08:29.220 that we talked about earlier 225 00:08:29.220 --> 00:08:31.650 that's included with most UEFI-based systems 226 00:08:31.650 --> 00:08:34.110 and this gives you better diagnostic tools and commands 227 00:08:34.110 --> 00:08:36.240 that you can use during your troubleshooting. 228 00:08:36.240 --> 00:08:38.010 Now, regardless of whether you're going to use 229 00:08:38.010 --> 00:08:40.830 a traditional BIOS or a newer UEFI-based system, 230 00:08:40.830 --> 00:08:42.690 you're going to be using this configuration tool 231 00:08:42.690 --> 00:08:45.900 to set up the boot order and the parameters for your system. 232 00:08:45.900 --> 00:08:46.950 This will allow you to determine 233 00:08:46.950 --> 00:08:48.510 which devices are going to be read from 234 00:08:48.510 --> 00:08:50.460 when you're trying to find the operating system, 235 00:08:50.460 --> 00:08:52.710 such as Windows, Linux or Mac OS 236 00:08:52.710 --> 00:08:54.660 for the system to be able to load. 237 00:08:54.660 --> 00:08:56.370 This can be your fixed storage device, 238 00:08:56.370 --> 00:08:59.340 something like a hard disk drive or a solid-state device. 239 00:08:59.340 --> 00:09:01.890 But you could also store it on an optical drive 240 00:09:01.890 --> 00:09:04.140 like a CD, DVD or Blu-ray, 241 00:09:04.140 --> 00:09:07.440 or a USB drive like a thumb drive or flash drive, 242 00:09:07.440 --> 00:09:09.630 or you might even use a network adapter 243 00:09:09.630 --> 00:09:12.900 to reach out to a server using the pre-execution environment 244 00:09:12.900 --> 00:09:15.570 known as PXE as your desired boot option. 245 00:09:15.570 --> 00:09:17.190 All of these are valid choices 246 00:09:17.190 --> 00:09:18.810 and it does depend on your use case. 247 00:09:18.810 --> 00:09:20.550 So it's an important thing for you to configure 248 00:09:20.550 --> 00:09:22.500 inside of your BIOS or UEFI 249 00:09:22.500 --> 00:09:24.240 as you pick out the prioritized list 250 00:09:24.240 --> 00:09:26.490 or boot order that you want to use. 251 00:09:26.490 --> 00:09:28.560 For example, let's say you have your set up 252 00:09:28.560 --> 00:09:30.660 to be the optical drive first, 253 00:09:30.660 --> 00:09:32.820 then the hard disk, then the USB, 254 00:09:32.820 --> 00:09:34.410 and then finally the network. 255 00:09:34.410 --> 00:09:36.090 This means when you turn on your computer, 256 00:09:36.090 --> 00:09:38.430 the system is first going to look to your optical drive 257 00:09:38.430 --> 00:09:41.100 to see if it can find a bootable operating system there. 258 00:09:41.100 --> 00:09:42.840 If it does, it's going to load it up. 259 00:09:42.840 --> 00:09:44.310 But if it doesn't, it's going to move on 260 00:09:44.310 --> 00:09:45.600 to your second priority 261 00:09:45.600 --> 00:09:48.060 which we listed as the hard disk drive. 262 00:09:48.060 --> 00:09:49.650 Now when it looks at your hard drive, 263 00:09:49.650 --> 00:09:51.510 it might find that Windows is installed. 264 00:09:51.510 --> 00:09:53.670 So it's going to then load up Windows 265 00:09:53.670 --> 00:09:55.080 and turn over control the system 266 00:09:55.080 --> 00:09:56.610 to the Windows operating system 267 00:09:56.610 --> 00:09:59.190 and it won't go any further down its boot list. 268 00:09:59.190 --> 00:10:02.310 But this particular order can actually be dangerous for you 269 00:10:02.310 --> 00:10:04.530 because there's a lot of operating systems out there 270 00:10:04.530 --> 00:10:07.380 that can be run from an optical drive or a USB thumb drive, 271 00:10:07.380 --> 00:10:09.450 such as certain versions of Linux. 272 00:10:09.450 --> 00:10:11.010 So as an attacker, 273 00:10:11.010 --> 00:10:14.460 if I can insert my Kali Linux DVD into your optical drive 274 00:10:14.460 --> 00:10:16.020 and power on your computer, 275 00:10:16.020 --> 00:10:17.430 I can now use your hardware 276 00:10:17.430 --> 00:10:19.350 and be able to bypass all of your passwords 277 00:10:19.350 --> 00:10:22.260 because I'm now loading up Kali Linux instead of Windows, 278 00:10:22.260 --> 00:10:24.180 and so I don't need to hack into your Windows account 279 00:10:24.180 --> 00:10:25.830 to use your system anymore. 280 00:10:25.830 --> 00:10:27.780 At this point from inside Kali Linux, 281 00:10:27.780 --> 00:10:28.890 I can mount your hard drive 282 00:10:28.890 --> 00:10:30.840 to read your files and things like that. 283 00:10:30.840 --> 00:10:32.940 But again, I would have to have physical access 284 00:10:32.940 --> 00:10:35.848 to your system to put that DVD into your drive. 285 00:10:35.848 --> 00:10:38.970 So for this reason, in most corporate environments, 286 00:10:38.970 --> 00:10:41.520 we like to use the best practice of disabling booting 287 00:10:41.520 --> 00:10:44.610 from an optical drive or USB drive to prevent attackers 288 00:10:44.610 --> 00:10:46.950 from taking over your systems in this way. 289 00:10:46.950 --> 00:10:48.840 Instead, you should configure your system 290 00:10:48.840 --> 00:10:50.490 to boot from your installed hard drive 291 00:10:50.490 --> 00:10:52.410 using the operating system you installed. 292 00:10:52.410 --> 00:10:54.090 Or if you're using a thin client, 293 00:10:54.090 --> 00:10:56.730 you may choose to boot the operating system over the network 294 00:10:56.730 --> 00:10:59.190 using PXE as your primary option 295 00:10:59.190 --> 00:11:02.730 and then not selecting optical drives or USB drives at all 296 00:11:02.730 --> 00:11:04.710 inside of your priority list. 297 00:11:04.710 --> 00:11:06.330 Now the final thing we need to discuss 298 00:11:06.330 --> 00:11:08.130 with the BIOS and UEFI 299 00:11:08.130 --> 00:11:11.040 is how to update it because this is software after all 300 00:11:11.040 --> 00:11:14.130 even if it is software on a chip or firmware. 301 00:11:14.130 --> 00:11:16.170 Now to update the BIOS or UEFI, 302 00:11:16.170 --> 00:11:18.480 you need to use a process known as flashing. 303 00:11:18.480 --> 00:11:20.580 Flashing is performed whenever there are upgrades, 304 00:11:20.580 --> 00:11:22.650 security fixes or feature improvements 305 00:11:22.650 --> 00:11:25.740 that need to be made to the BIOS or UEFI codebase. 306 00:11:25.740 --> 00:11:27.480 Always check the manufacturer's website 307 00:11:27.480 --> 00:11:29.010 for the latest firmware version 308 00:11:29.010 --> 00:11:30.270 and their specific process 309 00:11:30.270 --> 00:11:32.790 for flashing your BIOS or UEFI. 310 00:11:32.790 --> 00:11:33.630 In the old days, 311 00:11:33.630 --> 00:11:35.310 our systems actually didn't have the ability 312 00:11:35.310 --> 00:11:36.690 to flash the BIOS. 313 00:11:36.690 --> 00:11:38.280 And instead, we had to actually replace 314 00:11:38.280 --> 00:11:40.680 the entire BIOS chip on the motherboard. 315 00:11:40.680 --> 00:11:42.810 But thankfully, all modern motherboards 316 00:11:42.810 --> 00:11:44.160 now support flashing 317 00:11:44.160 --> 00:11:46.590 so we can simply overwrite the BIOS or UEFI 318 00:11:46.590 --> 00:11:48.750 using this specialized procedure. 319 00:11:48.750 --> 00:11:51.210 Now before flashing the BIOS or the UEFI, 320 00:11:51.210 --> 00:11:52.920 you should always backup your configuration 321 00:11:52.920 --> 00:11:54.300 and information first, 322 00:11:54.300 --> 00:11:56.120 just in case something does go wrong. 323 00:11:56.120 --> 00:11:57.100 In most systems, 324 00:11:57.100 --> 00:11:59.160 you're going to need a USB flash drive 325 00:11:59.160 --> 00:12:00.630 to flash your firmware. 326 00:12:00.630 --> 00:12:02.190 You'll then load a file into the root 327 00:12:02.190 --> 00:12:03.720 of that USB flash drive, 328 00:12:03.720 --> 00:12:04.710 connect the flash drive 329 00:12:04.710 --> 00:12:06.990 to the specified USB port on your motherboard, 330 00:12:06.990 --> 00:12:08.190 and then reboot the system 331 00:12:08.190 --> 00:12:10.320 while pressing a series of specified keys 332 00:12:10.320 --> 00:12:11.640 or pushing a specific button 333 00:12:11.640 --> 00:12:13.350 on the back of your motherboard. 334 00:12:13.350 --> 00:12:15.840 Then, the BIOS or UEFI will take over, 335 00:12:15.840 --> 00:12:17.430 copy the firmware to the system, 336 00:12:17.430 --> 00:12:18.780 and overwrite its old code 337 00:12:18.780 --> 00:12:20.883 with that newly updated firmware code.